Fumigants are among the most toxic and environmentally damaging pesticides still in wide use. Methyl bromide for example has been banned for its ozone depleting action. The continued use of these products reflects their unique ability to penetrate through a large volume of soil, structure, or agricultural commodity and then subsequently dissipate with no residue. The relatively unusual physical properties required for such products (high vapor pressure, non-flammable, non-reactive) have dramatically limited the number of options for fumigants. Most fumigants are extremely toxic and have non-specific modes of action. The discovery of Muscodor albus, an endophytic tropical fungus producing a highly potent biocidal mixture of volatile compounds, provided a natural product chemistry solution as an alternative to current fumigants. Natural products are often perceived to offer greater safety as well as lower environmental impact such that a biologically-derived fumigant would have great appeal to consumers. In addition, such product could serve the unmet need for fumigation in the organic food industry.
Previous publications regarding Muscodor albus note that no individual compound or class of compounds is lethal to any test microbes consisting of plant pathogenic fungi. A recent review of the Muscodor species states: “Obviously, the antibiotic effect of the VOCs of M. albus is strictly related to the synergistic activity of the compounds in the gas phase.” See Strobel, G., Phytochem. Rev. published online Feb. 16, 2010. As noted, the active substances of Muscodor albus have not previously been defined and therefore synthetic scale-up of a pesticide product derived from these substances was challenging. Described herein is a compound from Muscodor albus and a method for identifying the compound. Also described are compounds, compositions and kits that have similar structures or bioactivity to that of the active substances of M. albus. Methods of making the compounds described herein are also provided. The compounds and compositions described herein may be useful for control of fungal and bacterial pathogens, insect pests, acari, nematodes and other invertebrate pests, for example, for post-harvest and soil diseases, building mold remediation, and seed and grain sanitation. Also described are synthetic mixtures and kits comprising compounds herein that have similar efficacy to the Muscodor albus for treating disease.